Research On UTP Tunnel Adapter Based On Wireless CORBA

With the rapid development of wireless technology, extending distributed developments to mobile network have becoming more and more important. In order to extending the distributed object computing to mobile network, Wireless CORBA should meet two capital requirements: terminal mobility and wireless access, which traditional CORBA architecture is unable to deal with.For solving the problem of GIOP tunnel protocol mapping in Wireless CORBA architecture. In mobile network, traditional TCP will cause throughput decreasing and delay increasing, whereas UDP is a kind of trustless transport protocol, so it is very necessary to study GIOP tunnel adpter protocol-UTP implementing in Wireless CORBA.This paper provides the following contributions to the study of Wireless middleware technology at protocol layer. First, it analyzes the architecture and characters of wireless CORBA and makes an intensive study on the core supportive technology to realize wireless CORBA: mobile IOR, GIOP tunnel protocol and the diverse handoff mechanisms. Three different ARQ algorithms-SAW, GBN and SR, are also discussed and compared detailed.GIOP tunnel protocol, as an abstract, transport independent protocol, needs an adaptation layer residing between the GTP and the actual of transport protocol to provide the reliability and ordered delivery. Based on all above analysis and improvements, this paper designs a prototype of the UTP protocol, which consists of protocol behavior, message data structure and protocol function. By means of formal methodology design, it assures the least independent and a most abstract implementation of UTP. Thirdly, it explains how we applied layered software architecture to implement the UTP framework, focusing on throughput and reliability.At last, we test three performance measure tests, by taking Seawind emulator as the testing platform. The testing results show that the performance of UTP which take SR mechanism will be better than that of UTP which take GBN mechanism, when mobile network have high error rates, and the improved UTP could increase the utilizing rate of network.